JP6267139B2 - Rolling tapping device - Google Patents

Description

The present invention relates to a rolling tapping device capable of appropriately cooling a rolling tap and a nut blank when a female thread is formed by rolling in a pilot hole (preliminary hole) of a nut blank.

In mass production of nuts, generally, a nut blank is held in a fixed posture, and a rolling tap is rotationally press-fitted into the nut blank to plastically deform a prepared hole wall surface to form a female screw. This operation is generally performed by arranging the axial direction of the pilot hole up and down, holding the nut blank by the processing part jig, inserting the rolling tap into the pilot hole from above and inserting it under the nut blank. A female thread corresponding to the rolling thread of the rolling tap is plastically formed on the hole wall surface.
Naturally, with such processing, the tap and the nut blank as the workpiece inevitably generate heat, and the heat generation causes wear of the tap and processing failure of the workpiece.
For this reason, conventionally, in order to cool the tap and nut blank, a guide groove is formed in the longitudinal direction of the outer peripheral surface of the rolling tap so that liquid coolant is poured from the upper side of the rolling tap toward the workpiece. To cool both.

However, even if such a method is adopted, it cannot be a sufficient countermeasure. In other words, with such conventional measures, heat is generated most severely during processing, and the load is large for the tap. Liquid coolant is not supplied directly to the tap tip (processing start portion), but certain results have been obtained. The tool life was short. Specifically, although it depends on the size of the nut, when processing with a nominal diameter of about M10 to M20, it is necessary to replace with about 2000 to 3000 per tap, and the daily production amount is 12000. Then, consumption of 4 to 6 taps was observed.
This situation is not limited to the consumption of the tap, and the work efficiency is significantly reduced when the labor required for the replacement work, especially the adjustment until the steady operation after the replacement is obtained is taken into consideration. In addition, the daily production volume means 24 hours of operation by operating an automatic machine, so the tap change interval is also outside of normal working hours such as night, midnight, and early morning. It was a burden.
Of course, measures are taken such as providing a plurality of flow guide grooves for the tap to promote cooling by liquid coolant, but if the flow guide grooves are increased, the molding pile (rolling pile) is divided accordingly. As a result, the strength is reduced, and even if such measures are taken, the durability is only about 1.5 to 2 times, and the effect is such that no replacement is required at the end of the day. Cannot be obtained.

By the way, it has already been widely performed in machining centers and the like that a necessary portion is effectively cooled and processed while discharging liquid coolant from the blade edge portion. However, as is well known, a machining center performs a plurality of complicated processes according to a computer program, and in order to comply with the request, for example, a drill chuck or a spindle unit for driving a drill is provided with a cutting fluid supply function, and the apparatus is complicated. Even if it is, it is sufficiently acceptable.
However, such a manufacturing method using a machining center is inappropriate and out of the question for mass-producing the same part with the machining tact time reduced as much as possible. Accordingly, a general-purpose tapping machine having a simple tap chuck and a driving spindle is used, and it is impossible to envisage such a device to supply liquid coolant into the tap.

  In other words, it has been devised to form a lubricating oil passage inside the tap in the rolled tap and then flow the lubricating oil to the outer periphery of the tap tip (see, for example, Patent Document 1). However, in this case, if it is assumed that a conventional general-purpose tapping machine is used, it has been necessary to change to a structure that can supply lubricant from the chuck part or the drive part that holds the tap (a significant structural change). Was necessary). As a result, the conventional liquid coolant supply method is a flow from the upper side of the rolling tap toward the nut blank as already described, and the above problem remains unresolved. Has reached the present.

JP 2010-184339 A

The present invention has been made in view of such various backgrounds, and can effectively supply the liquid coolant to the processing start portion at the tip of the tap while assuming the use of a simple general-purpose tapping machine. Thus, the development of a new rolling tapping device that can cool the part that generates heat most intensively was a technical problem.

That is, the rolling tapping device according to claim 1 is:
The nut blanks that are sequentially supplied are held in an appropriate posture, and a rolling tap is rotationally press-fitted into the prepared hole that is drilled through the nut blank, and the rolling tap is formed on the inner wall of the prepared hole. A tapping device for plastically forming a corresponding female screw,
The processing part jig for holding the nut blank is provided with an end face support that supports one end face of the nut blank, and a non-rotating clamp that prevents rotation of the nut blank in forming the female thread,
The end face support includes a liquid coolant supply path, and the discharge opening is opened so as to face a pilot hole of a nut blank clamped by a non-rotating clamp,
On the other hand, the rolling tap has a dead end-like liquid supply space from the tip to the back, and a supply hole is formed in the rolling tap from the liquid supply space toward the rolling mountain side, Furthermore, a flow guide groove communicating with the outer periphery of the rolling tap is formed at the outlet end of the supply hole.

Further, the rolling tapping device according to claim 2 is in addition to the requirements of claim 1 ,
The end face support in the processed part jig is to support one end face of the nut blank from below, and the corresponding rolling tap acts on the nut blank from above,
Further, the liquid coolant is discharged from the discharge opening in the end surface support, is sent upward in the nut blank, and is supplied to the outer side of the rolling tap from the diversion groove via the liquid supply space and supply hole of the rolling tap. It is characterized by being configured to flow out.

Further, the rolling tapping apparatus according to claim 3 is in addition to the requirements of claim 1 or 2 ,
The end surface support is configured to be slidable in the processing part jig, and at the end of the internal thread forming process of the nut blank, the end surface support is retracted from the actual processing stage where the processing by the rolling tap is substantially performed, and the end surface support of the processed nut is performed. And the processed nut is dropped and recovered.

Further, the rolling tapping device according to claim 4 is in addition to the requirements of claim 1, 2, or 3 ,
The processing part jig comprises a slide clamp that individually pushes a nut blank that is sequentially supplied to an actual processing stage where processing by a rolling tap is substantially performed,
In addition, the slide clamp is characterized in that it cooperates with a fixed clamp provided opposite to the slide clamp in the actual machining stage to sandwich the nut blank to constitute the detent clamp.

Further, the rolling tapping apparatus according to claim 5 is in addition to the requirements of claim 1, 2, 3 or 4 ,
The nut blank to be sequentially supplied is formed so that the opening diameter of the pilot hole is different on both end faces,
Further, the processing part jig is provided with an inspection stage for determining whether or not the nut blank is in an appropriate posture in the previous stage of the actual processing stage where the processing by the rolling tap is substantially performed.
In this inspection stage, the probe that enters and does not enter the pilot hole due to the difference in the upper and lower opening diameters of the nut blank is operated, the posture of the nut blank is determined by the difference in the moving stroke, and only the nut blank in the proper posture is Is sent to the actual machining stage and is subjected to plastic working by rolling taps.

The first According to the first aspect of the invention, the route for supplying liquid coolant to the rolling tap during processing, through the rolling tap from the tap tip side (liquid supply space) a (supply hole), rolling tap Since it is a route that leads to the outer peripheral part (conveying groove) and sends it from here to the rolling mountain near the tip of the rolling tap (processing start part), it is effective even assuming that a simple general-purpose tapping machine is used. Liquid coolant can be supplied to the processing start portion on the outer peripheral side of the tap tip. Incidentally, the method of supplying liquid coolant through the tap from the direction of chucking the rolling tap (press-fit direction) needs to be reviewed from the holding structure of the machine (tapping machine) that chucks the rolling tap. It was a technique that cannot be premised on the use of.
In addition, since the processing start part on the outer periphery side of the tap tip is the part that generates the most heat during processing, efficiently supplying the liquid coolant to the processing start part cools the part intensively. As a result, the entire processing can be performed smoothly. For this reason, more nut blanks can be processed with a single rolling tap, and the number of rolling taps that are worn out in a day can be reduced. Possible). Furthermore, setting work associated with replacement of the rolling tap can be reduced, and total work efficiency and manufacturing cost can be reduced.

According to the second aspect of the present invention, during processing, the posture of the nut blank is a posture in which both end faces (prepared holes) of the nut are directed up and down, and the press-fitting direction of the rolling tap is also from the upper side to the lower side. In addition, since the liquid coolant is supplied into the prepared hole of the nut blank from below, a processing mode more consistent with the usage pattern of a general-purpose tapping machine can be taken and the processing can be easily performed. This is a preferable mode for an operator who handles a tapping machine because his / her experience and feeling can be utilized.

According to the third aspect of the present invention, at the end of the female thread forming process, the end face support that has supported the nut blank is moved away from the actual processing stage, and the processed nut is dropped and collected downward. The nuts (nut blanks) after the female thread formation can be reliably and efficiently recovered without leaving, and the rolling process (female thread forming process) to the nut blanks supplied one after another can be performed smoothly. .

According to the invention described in claim 4 , the nut blank can be surely fed to the actual machining stage one by one by the slide clamp, and the actual rolling tapping can be performed more efficiently.
In addition, the slide clamp that feeds the nut blank to the actual machining stage is used as one component of the detent clamp (to form the detent clamp by the slide clamp and the fixed clamp), and the nut blank is fed to the actual machining stage. Can be smoothly and reasonably performed, contributing to simplification of constituent members, simplification of the apparatus configuration, and the like.

Further, according to the invention described in claim 5, before performing the plastic working by the actual rolling tap, the posture of the nut blank is inspected, and the proper posture is sent to the actual processing stage. Rolling taps can be press-fitted for efficient processing. Further, since the actual female thread forming process is not performed on the nut blank in an inappropriate posture, the rolling tap can be effectively used without damaging the rolling tap.

The perspective view (a) which shows skeletally how a female thread is plastically formed in the inner wall of a pilot hole of a nut blank by applying the rolling tap according to the present invention, and a front view, a bottom view, and a longitudinal sectional view of the rolling tap ( Longitudinal sectional view mainly showing a liquid supply space and a supply hole (b), and a longitudinal sectional view (c) showing an example of a nut blank (before female thread forming processing) in which a pilot hole is formed, and at the time of female thread forming processing The liquid coolant is supplied to the rolling tap through the pilot hole of the nut blank, and the liquid coolant passes through the liquid supply space in the rolling tap, the supply hole, and the guide groove in order, It is explanatory drawing (d) which shows a mode that it reaches | attains a process start part. It is the front view and side view which show an example of the rolling tapping apparatus (whole apparatus) of this invention. It is a perspective view which shows skeleton the periphery (a slide clamp and the periphery of a fixed clamp) of an inspection stage and an actual processing stage in a rolling tapping device. It is explanatory drawing which shows a mode that the attitude | position of the nut blank supplied to the test | inspection stage is determined, (a) is an appropriate attitude, (b) is an improper attitude. It is explanatory drawing which shows a mode that a nut blank is supplied to a test | inspection stage one by one from a plane and a side direction. An explanatory view showing the state in which the nut blank is transferred from the inspection stage to the actual processing stage from the plane and side directions, and in the actual female thread forming processing, the liquid coolant is made to penetrate the inside of the rolling tap and the outer periphery of the rolling tap ( It is explanatory drawing which shows a mode that it reaches | attains a process start part). It is explanatory drawing which shows a mode that the processed nut (nut blank) in which the internal thread was formed is dropped and collect | recovered from a side surface direction.

  The mode for carrying out the present invention includes one described in the following embodiments, and further includes various methods that can be improved within the technical idea.

  In the present invention, as an example, as shown in FIGS. 1A and 1C, a rolling tap 10 is rotationally press-fitted into a nut blank W that is formed by previously opening a pilot hole (preliminary hole) H in a penetrating state. In addition, the present invention relates to a rolling tapping that plastically forms a female thread on the inner wall surface of the prepared hole H (so-called “rise tap”). Specifically, as shown in FIG. 1D as an example, during the internal thread forming process, liquid coolant (from the tip side of the rolling tap 10 (opposite to the press-fitting direction) into the pilot hole H of the nut blank W Lubricating oil) C is supplied, and this liquid coolant C then passes through the rolling tap 10 and reaches the outer peripheral side (processing start portion) of the rolling tap 10, which is the present invention. It is a big feature. As a result, generation of large frictional heat generated at the processing start portion during processing can be suppressed, and the processing start portion of the rolling tap 10 can be intensively cooled, so that the female thread can be formed smoothly.

Moreover, since the supply route of the liquid coolant C is configured as described above, as the rolling tap 10, as shown in FIG. 1B as an example, a tap main body 11 having a relatively short rod shape and The spiral rolling mountain 12 formed on the outer peripheral side of the tap body 11, the dead end liquid supply space 13 formed from the tip of the tap toward the back of the tap, and the outer peripheral side rolling from the liquid supply space 13. It comprises a supply hole 14 formed penetrating toward the mountain formation 12 and a flow guide groove 15 formed in communication with the outlet end of the supply hole 14.
Here, for example, in FIG. 1 (b), four supply holes 14 are formed as flow paths extending radially from the center of the tap body 11. In addition, the diversion grooves 15 are formed at eight locations so as to divide the rolling ridges 12 along the axial direction of the tap main body 11, and the diversion grooves 15 that communicate with the supply holes 14, and the diversion grooves 15 that do not communicate with each other. Are formed alternately on the outer periphery of the tap body 11. As a result, the liquid coolant C supplied from the pilot hole H of the nut blank W to the tip side of the rolling tap 10 passes through the rolling tap 10 in order of the liquid supply space 13 and the supply hole 14, and is rolled. It reaches the flow guide groove 15 on the outer peripheral portion of the tap 10 and reaches the tip end of the tap (which is also referred to as “processing start portion” in the present specification) on which the rolling process (plastic processing) is performed, and the part is concentrated. Cool down.

Next, the rolling tapping apparatus 1 that rotationally press-fits the rolling tap 10 into the nut blank W and plastically forms female threads on the inner wall surface of the pilot hole H will be described.
As shown in FIG. 2 and FIG. 3 as an example, the rolling tapping apparatus 1 includes a processing unit jig 2 that holds a nut blank W to be processed in a fixed posture (appropriate posture) as a main component member. Can also be said to be the apparatus main body or processing table of the rolling tapping apparatus 1.
In this embodiment, the rolling tapping is performed in a posture in which the pilot hole H opened in the nut blank W is directed up and down (a so-called standing posture in which both end surfaces of the nut are directed up and down). Therefore, the direction in which the rotating rolling tap 10 is press-fitted into the nut blank W (the pilot hole H) is also downward from above.

In addition, as shown in FIG. 3 as an example, the processing unit jig 2 sequentially includes an inspection stage S1 that detects whether or not the supplied nut blank W is in an appropriate posture, and a nut blank W that has been determined to be in an appropriate posture. Only an actual processing stage S2 which performs a substantial rolling tapping process (female thread forming process) only.
That is, in this embodiment, the pilot hole H of the nut blank W is formed so that the opening diameters of both end faces are different as shown in FIG. In the actual female thread forming process, the rotating rolling tap 10 is press-fitted from the large diameter side of the pilot hole H (see FIG. 1D). For this reason, in this embodiment, such an inspection stage S1 is provided, and only the nut blank W in an appropriate posture is subjected to actual female thread forming processing.
As a specific detection method, as shown in FIG. 4 as an example, the probe 51 is inserted into the pilot hole H of the nut blank W supplied to the inspection stage S1 (here, descending from above to below), Due to the difference in the moving stroke, only the proper posture is transferred to the actual machining stage S2 (the nut blank W having an improper posture is excluded).

In addition, a supply device 7 for supplying the nut blanks W to the processing unit jig 2 one by one is provided in front of the processing unit jig 2 (inspection stage S1). As this supply device 7, for example, an alignment conveyance device (so-called parts feeder) using gravity sliding can be applied. More specifically, for example, as shown in FIGS. 2 and 3, a plurality of nut blanks W are conveyed onto the inspection stage S <b> 1 while being aligned in a daisy-chained manner on an inclined table (slide table) 71. Of course, when the nut blank W is finally supplied to the inspection stage S1, the nut blanks W are pushed in one by one.
When the nut blank W is supplied from the supply device 7 (tilting base 71) to the inspection stage S1, for example, as shown in the plan view of FIG. 5, the front and rear nut blanks W contact the side surfaces of the nuts. Supplied in a connected state (continuous state). In the present embodiment, as an example, the first nut blank W (the nut blank W positioned immediately before the inspection stage S1) is inspected only when 22 nut blanks W are arranged in a daisy chain on the inclined base 71. It is configured to send to stage S1.
That is, the front side of the inspection stage S1 in the processing section the jig 2, the supply guide groove 53 is formed for receiving a nut blank W which has been transferred from the supply device 7, slides down ramp 71 of the feeder 7 The nut blank W has been guided to enter the supply guide groove 53 as it is. The supply guide groove 53 is formed so as to be somewhat narrowed toward the inspection stage S1, so that the nut blank W can be easily received from the supply device 7 (tilt base 71).
In this way, the load of the nut blank W arranged behind it acts on the leading nut blank W. In other words, the leading nut blank W always receives the pushing of the nut blank W attached behind it. Further, since the nut blank W is guided to the supply guide groove 53, the nut blank W is substantially horizontal and does not lie down while being supplied to the inspection stage S1.

Moreover, the processing part jig | tool 2 is provided with the end surface support 3 which supports one end surface of the nut blank W, and supports the opening edge part by the side of a small diameter from a downward direction in a present Example.
Further, the processing part jig 2 includes a detent clamp 4 that holds and fixes the nut blank W into which the rolling tap 10 is rotationally press-fitted in the actual processing stage S2 so as not to rotate during processing.
As shown in FIG. 3 and FIG. 5 as an example, the non-rotating clamp 4 includes a slide clamp 41 for individually pushing the nut blank W from the inspection stage S1 to the actual machining stage S2, and the slide in the actual machining stage S2. It is comprised by the clamp 41 and the fixed clamp 42 provided facing, and in actual process stage S2, these are cooperated and it is comprised so that nut blank W may be clamped firmly.
Specifically, as shown in the plan view of FIG. 5 as an example, the sandwiching portion between the slide clamp 41 and the fixed clamp 42 is configured to have a “V” shape so that the nut blank W faces each other. It is something that is sandwiched between.

In this configuration, when the nut blank W is transferred from the inspection stage S1 to the actual machining stage S2, the nut blank W is transferred while receiving the nut blank W exclusively at the working end (V-shaped portion) of the slide clamp 41. However, since the operating end of the slide clamp 41 is V-shaped, the center of the nut blank W can be automatically adjusted, thereby the center of the nut blank W (the pilot hole H) transferred to the actual machining stage S2 is The structure is easy to match the center of the rolling tap 10. In particular, when a part of the nut blank W has an external cylindrical shape as shown in FIG. 1 (a) as an example, the core as described above can be accommodated in the V-shape of the slide clamp 41. It is easy to match.
Incidentally, reference numeral 33 in the figure denotes a slide guide groove in which the slide clamp 41 pushes the nut blank W in an appropriate posture to the actual machining stage S2, and the transfer start portion of the slide guide groove 33 is the inspection stage S1, the transfer end. The part becomes the actual machining stage S2.
Thus, the nut blank W is not only pushed by the slide clamp 41 during the transfer from the inspection stage S1 to the actual machining stage S2, but both sides are regulated by the slide guide groove 33. Appropriate posture is maintained (does not fall sideways, etc.).

Next, the inspection stage S1 will be described in more detail.
As described above, the inspection stage S1 is a stage that detects whether or not the posture of the nut blank W individually supplied to the inspection stage S1 is appropriate. The inspection stage S1 includes the posture detection device 5. Is provided. As shown in FIG. 4 as an example, the posture detection device 5 includes a probe 51 that can enter the pilot hole H of the nut blank W supplied to the inspection stage S1 as a main constituent member.
Here, the proper posture of the nut blank W will be described. As an example, as shown in FIG. 1 (c), the posture with the large-diameter opening end facing upward and the small-diameter opening end facing downward is the proper posture. Appropriate posture. Note that when the nut blank W is supplied to the inspection stage S1, the nut blank W takes any one of these postures and is not supplied in a sideways posture. This is because, as described above, the supply device 7 is supplied in a state (standing position) with the pilot hole H facing upward or downward. That is, by providing, for example, standing walls on both sides of the tilting table 71, when the nut blanks W are arranged in a daisy chain on the tilting table 71, the standing posture with the pilot hole H facing up or down is arranged. Can be regulated. In other words, by adopting such a configuration, the nut blank W is prevented from falling while the nut blank W is being supplied from the supply device 7 (tilt base 71) to the inspection stage S1.

In addition, as shown in FIG. 4, the probe 51 has an insertion end inserted into the pilot hole H of the nut blank W. The inner space is substantially matched. Therefore, when the probe 51 is inserted into the pilot hole H of the nut blank W (here, descending from above), the nut blank W is in an appropriate posture (the large-diameter opening end is upward, the small-diameter is small), as shown in FIG. If the open end is down), the probe 51 moves a relatively long distance and fits within the pilot hole H. On the other hand, as shown in FIG. 4B, if the nut blank W is in an inappropriate posture (the large diameter opening end is down and the small diameter opening end is up), the entry of the probe 51 is blocked by the small diameter side opening end. The distance movement becomes shorter. Thus, in the present embodiment, the posture of the nut blank W supplied to the inspection stage S1 is detected based on the difference in the moving distance (here, the downward stroke) of the probe 51 entering the pilot hole H.
It should be noted that the nut blank W that has been found to be in an inappropriate posture as a result of the inspection is not sent to the subsequent actual machining stage S2, but is removed from the machining line, for example, may be reinserted into the supply device 7. preferable.
Incidentally, reference numeral 52 in FIG. 5 is a proximity sensor that senses that the nut blank W has been supplied (reached) to the inspection stage S1, and after the proximity sensor 52 detects supply of the nut blank W. It is preferable to control the probe 51 to automatically enter the nut blank W. As shown in the plan view of FIG. 5, the slide guide groove 33 is formed so as to be substantially orthogonal to the supply guide groove 53, and the supply guide groove 53 in the slide guide groove 33 (inspection stage S1). The proximity sensor 52 is provided on the abutting wall from the side.

Next, the actual machining stage S2 will be described.
As described above, the actual machining stage S2 substantially rotationally presses the rolling tap 10 into the nut blank W sent from the inspection stage S1 in an appropriate posture, and sets the female thread corresponding to the rolling pile of the rolling tap 10. It is a stage for plastic forming (so-called “rise tap”).
In this actual machining stage S2, as described above, a detent clamp 4 that holds and holds the nut blank W so as not to rotate during machining is configured.

Further, as shown in the side view (side sectional view) of FIG. 6 as an example, the end surface support 3 in the actual processing stage S2 is formed with a feed path 31 for the liquid coolant C, and the discharge opening 32 is formed in the actual processing stage S2. An opening is made so as to face the pilot hole H (small diameter side opening) of the nut blank W clamped by the detent clamp 4 in the stage S2.
That is, the liquid coolant C is discharged from the feed path 31 (discharge opening 32) into the pilot hole H of the nut blank W during the actual processing in which the rolling tap 10 is rotationally press-fitted into the nut blank W in the actual processing stage S2. . In this way, the liquid coolant C is supplied from the tip end side (opposite to the press-fitting direction) of the rolling tap 10, and then, as an example, as shown in FIG. 1D and the enlarged view of FIG. Then, the liquid supply space 13 in the rolling tap 10 and the supply hole 14 are sequentially passed to reach the flow guide groove 15 on the outer periphery of the rolling tap 10, and reach the machining start portion through this flow guide groove 15. It cools intensively.

  In addition, since the liquid coolant C after cooling the rolling tap 10 falls naturally, a saucer, a tank, etc. are provided in the lower part of the processing part jig 2, and the liquid coolant C falling after use is used. It can be collected in the tray or tank and circulated with a pump. In that case, of course, foreign substances (such as dust) that may be contained in the used liquid coolant C are circulated and used while removing them as much as possible.

In addition, the end surface support 3 that supports the nut blank W in the actual machining stage S2 is configured so as to be retracted from the actual machining stage S2 by an air cylinder or the like as shown in FIG. The finished processed nut (nut blank W) is configured to drop and discharge downward.
The nut dropped and discharged from the actual processing stage S2 is appropriately transported to a desired position by a conveyor or the like and collected.

Rolling tapping device 1 of the present invention are those having the basic structure described above, hereinafter while explaining the operation manner of plastically forming an internal thread in the nut blank W by applying this device, roll forming tapping method Will also be described.
In addition, as mentioned above, the pilot hole H is previously opened in the nut blank W in the penetrating state, and in particular, in this embodiment, the opening diameters at both ends of the nut are different.
(1) Supply of nut blank (supply to inspection stage)
In order to supply the nut blank W in which the pilot hole H is opened to the inspection stage S1 of the processing unit jig 2, the supply device 7 is applied as described above, and the posture of the nut blank W at this time is The pilot hole H (both end surfaces of the nut) is supplied (introduced) to the inspection stage S1 in a standing posture (appropriate posture or vice versa) with the pilot hole H (both end surfaces of the nut) facing up and down.
In particular, in this embodiment, the nut blanks W are arranged in a daisy chain on an inclined base 71 provided in the supply device 7, and are supplied while sliding down in this state. The nut blanks W are connected to the inspection stage S1 one by one after a certain number (for example, 22) of the nut blanks W are connected in a daisy chain. That is, as an example, after the 22 nut blanks W are connected in a daisy chain, the first nut blank W (the nut blank W positioned immediately before the inspection stage S1) is controlled to be fed into the inspection stage S1 for the first time. .

By doing in this way, since the load of the nut blank W arranged in the back side acts on the head nut blank W (because the head nut blank W always receives pushing from the back), inspection stage S1 The nut blank W waiting to be supplied to the side does not lie sideways, and the posture in which the pilot holes H (both end surfaces of the nut) are directed up and down is maintained. For this reason, in the inspection stage S1, when inspecting the posture of the nut blank W, it is only necessary to consider the upper and lower sides.
The supply of the nut blank W to the inspection stage S1 is started when the pushing tip (V-shaped portion) of the slide clamp 41 returns from the actual processing stage S2 to the inspection stage S1 side (a daisy chain-shaped nut blank). W moves forward to the inspection stage S1 side by one as a whole). In other words, for example, as shown in the plan view of FIG. 6, when the slide clamp 41 pushes the nut blank W into the actual machining stage S2, or when the nut blank W is clamped by the actual machining stage S2, Since the main body portion of the slide clamp 41 is located on the inspection stage S1, the supply of the nut blank W (supply from the supply device 7) is cut off (interrupted).

(2) Posture Inspection at Inspection Stage As described above, the nut blanks W are supplied (pushed) from the supply device 7 to the inspection stage S1 one by one. Here, the fact that the nut blank W has been sent to the inspection stage S1 is detected by, for example, the proximity sensor 52 provided on the inspection stage S1. Then, by this sensing, the probe 51 of the posture detection device 5 is automatically entered (lowered) into the nut blank W located on the inspection stage S1.
As described above, the pilot hole H opened in the nut blank W has different opening diameters at both ends. For this reason, in this embodiment, the difference in opening diameter is used to supply the inspection stage S1. The posture of the nut blank W is inspected. That is, as shown in FIG. 4A as an example, if the nut blank W is in an appropriate posture (the large diameter opening end is up and the small diameter opening end is down), the probe 51 is almost contained in the pilot hole H. 51 distance movement also becomes longer. On the other hand, as shown in FIG. 4B as an example, if the nut blank W is in an inappropriate posture (large diameter opening end is down and small diameter opening end is up), the entry of the probe 51 is blocked by the small diameter side opening end. Rarely, the distance movement becomes shorter. Thus, in the present embodiment, the posture of the nut blank W supplied to the inspection stage S1 is detected based on the difference in the moving distance (here, the downward stroke) of the probe 51 entering the pilot hole H.
Then, only the nut blank W in an appropriate posture for which an OK determination is obtained in this posture inspection is supplied (sent into) the subsequent actual machining stage S2. On the other hand, the nut blank W in the improper posture (upside down from the proper posture) for which NG is determined in the inspection stage S1 is excluded from the processing line. However, it is preferable that the nut blank W in an inappropriate posture excluded from the processing line is not defective in shape such as the pilot hole H, and is therefore returned to the supply device 7 again and used for processing.

(3) Transfer from Inspection Stage to Actual Processing Stage The nut blank W that has been confirmed to be in the proper posture in the inspection stage S1 is, for example, as shown in FIGS. It is pushed in by a V-shape in plan view and transferred (supplied) to the actual machining stage S2. Further, as described above, the slide guide groove 33 for guiding the transfer of the nut blank W is formed from the inspection stage S1 to the actual processing stage S2, and the nut blank W is regulated on both sides by the slide guide groove 33. It is supplied up to the actual machining stage S2.
As described above, since the restriction by the slide guide groove 33 and the pushing action end of the slide clamp 41 are V-shaped in a plan view, the nut blank W is maintained in an appropriate posture during transfer and reaches the actual machining stage S2. is there. That is, the nut blank W does not rotate during the transfer from the inspection stage S1 to the actual processing stage S2, or does not fall on its side.
Since the working end of the slide clamp 41 is V-shaped in a plan view, for example, as shown in FIG. 1A, the portion pushed by the working end (the pressed portion of the nut blank W) has an outer cylindrical shape. Then, the center of the nut blank W can be automatically aligned, and the centering with the rolling tap 10 in the actual machining stage S2 can be easily performed. That is, the center of the nut blank W (the pilot hole H) fed to the actual machining stage S2 can be easily matched with the center of the rolling tap 10.

(4) Female thread formation on the actual processing stage (plastic formation of female threads)
As an example, the nut blank W transferred to the actual machining stage S2 is fixed to the slide clamp 41 into which the nut blank W has been pushed and the actual machining stage S2, as shown in the plan view of FIG. It is clamped by the fixed clamp 42 and is firmly clamped so as not to rotate during processing. In other words, the nut blank W transferred to the actual machining stage S2 is firmly held so as not to rotate during machining by the anti-rotation clamp 4 configured by the slide clamp 41 and the fixed clamp 42 arranged to face each other.

When the nut blank W is firmly clamped in the actual processing stage S2 as described above, the rolling tap 10 is rotated into the pilot hole H of the nut blank W as shown in a side view (side sectional view) of FIG. (In this case, the rolling tap 10 is lowered while being rotated).
In addition, the process by the rolling tap 10 is a process in which a female thread is plastically formed on the inner wall surface of the pilot hole H (so-called raised tap), and since it is not cutting, chips are not produced during processing, but especially at the tip of the tap. It generates a lot of heat at the processing start part. Therefore, this heat generation is suppressed (that is, the frictional resistance between the rolling tap 10 and the nut blank W is reduced), and the liquid coolant C is intensively supplied to the processing start portion in order to perform plastic processing smoothly. Hereinafter, this supply mode will be described.

(5) Supply of Liquid Coolant In the actual machining stage S2, the discharge opening 32 for the liquid coolant C is formed in the end surface support 3 that holds the nut blank W as described above. This discharge opening 32 is opened so as to face the pilot hole H of the nut blank W clamped in the actual machining stage S2. For this reason, the liquid coolant C supplied (discharged) from the discharge opening 32 reaches the inside of the pilot hole H from the small diameter side (lower side) opening of the nut blank W as shown in the enlarged view of FIG. The liquid supply space 13 is reached. Thereafter, the liquid coolant C sequentially reaches the rolling mountain 12 on the outer peripheral portion of the tap, that is, the processing start portion via the supply hole 14 and the flow guide groove 15 penetrating from the liquid supply space 13 to the inside of the tap. Cool intensively.
Thus, in the present invention, the liquid coolant C is supplied to the pilot hole H of the nut blank W from the side opposite to the tap press-fitting direction, and is then passed through the inside of the rolling tap 10 being processed and sent to the outer peripheral portion of the tap. Thus, the processing start portion that generates the most heat can be effectively cooled. In addition, the rolling tapping process can be performed smoothly and the tool life of the rolling tap 10 can be extended (the entire day can be used without replacing the rolling tap 10). The number of production per tap (number of nuts produced) can also be increased.
Of course, when supplying the liquid coolant C to the rolling tap 10, in addition to the above-described method (how to feed to the outer peripheral side through the inside of the rolling tap 10), the nut blank W from the upper side of the rolling tap 10. The liquid coolant C may be poured toward the surface.
In addition, the liquid coolant C which mainly cooled the processing start part of the rolling tap 10 can be recovered and recycled.

(6) Dropping and discharging of processed nuts After forming the female thread on the inner wall surface of the prepared hole of the nut blank W, turn the rolling tap 10 while rotating the rolling tap 10 in the direction opposite to that at the time of female thread formation. Pull out from the nut blank W (here, pull up).
Then, as shown in FIG. 7 as an example, the end face support 3 holding the nut blank W is moved away from the actual processing stage S2, and the processed nut (nut blank W) is held (supported) in the actual processing stage S2. To release.
In addition, with the release of the lower support by the end surface support 3, with respect to the detent clamp 4, the slide clamp 41 is slightly slid (returned) from the actual processing stage S 2 to the inspection stage S 1 side, and a processed nut ( The clamp of nut blank W) is also released.
By doing so, all the holding force acting on the processed nut is released, and the processed nut on which the female screw is formed falls downward and is appropriately recovered by a conveyor or the like.

(7) Return of slide clamp Further, after such a processed nut (nut blank W) is dropped, the slide clamp 41 (tip pushing action portion) is completely returned to the inspection stage S1 side as an example, as shown in FIG. As shown in the plan view, one nut blank W is supplied from the supply device 7 to the inspection stage S1, and the above processing is repeated thereafter.

DESCRIPTION OF SYMBOLS 1 Rolling tapping apparatus 2 Processing part jig | tool 3 End surface support 4 Non-rotating clamp 5 Posture detection apparatus 7 Supply apparatus

S1 Inspection stage S2 Actual machining stage

DESCRIPTION OF SYMBOLS 10 Rolling tap 11 Tap main body 12 Rolling mountain 13 Liquid supply space 14 Supply hole 15 Conveyance groove

3 End face support 31 Supply path (liquid coolant supply path)
32 Discharge opening 33 Slide guide groove

4 Non-rotating clamp 41 Slide clamp 42 Fixed clamp

5 Attitude detection device 51 Probe 52 Proximity sensor 53 Supply guide groove

7 Supply device 71 Tilting table

W Nut blank H Pilot hole C Liquid coolant (lubricant)

Claims (5)

The nut blanks that are sequentially supplied are held in an appropriate posture, and a rolling tap is rotationally press-fitted into the prepared hole that is drilled through the nut blank, and the rolling tap is formed on the inner wall of the prepared hole. A tapping device for plastically forming a corresponding female screw,
The processing part jig for holding the nut blank is provided with an end face support that supports one end face of the nut blank, and a non-rotating clamp that prevents rotation of the nut blank in forming the female thread,
The end face support includes a liquid coolant supply path, and the discharge opening is opened so as to face a pilot hole of a nut blank clamped by a non-rotating clamp,
On the other hand, the rolling tap has a dead end-like liquid supply space from the tip to the back, and a supply hole is formed in the rolling tap from the liquid supply space toward the rolling mountain side, Further, a rolling tapping device is characterized in that a flow guide groove communicating with the outer periphery of the rolling tap is formed at the outlet end of the supply hole.
The end face support in the processed part jig is to support one end face of the nut blank from below, and the corresponding rolling tap acts on the nut blank from above,
Further, the liquid coolant is discharged from the discharge opening in the end surface support, is sent upward in the nut blank, and is supplied to the outer side of the rolling tap from the diversion groove via the liquid supply space and supply hole of the rolling tap. rolling tapping device of claim 1, characterized in that it is arranged to flow out to.
The end surface support is configured to be slidable in the processing part jig, and at the end of the internal thread forming process of the nut blank, the end surface support is retracted from the actual processing stage where the processing by the rolling tap is substantially performed, and the end surface support of the processed nut is performed. The rolling tapping device according to claim 1 or 2, wherein the processed nut is dropped and collected by dropping the processed nut.
The processing part jig comprises a slide clamp that individually pushes a nut blank that is sequentially supplied to an actual processing stage where processing by a rolling tap is substantially performed,
And the slide clamp is in the actual machining stage in cooperation with the fixed clamp is provided to the slide clamp and the counter, said claim pinch nut blank, characterized in that it constitutes the detent clamp 1 Or the rolling tapping apparatus of 3 description.
The nut blank to be sequentially supplied is formed so that the opening diameter of the pilot hole is different on both end faces,
Further, the processing part jig is provided with an inspection stage for determining whether or not the nut blank is in an appropriate posture in the previous stage of the actual processing stage where the processing by the rolling tap is substantially performed.
In this inspection stage, the probe that enters and does not enter the pilot hole due to the difference in the upper and lower opening diameters of the nut blank is operated, the posture of the nut blank is determined by the difference in the moving stroke, and only the nut blank in the proper posture is The rolling tapping device according to claim 1, 2, 3, or 4, wherein the plastic tape is fed to an actual machining stage to perform plastic working by a rolling tap.

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